From: Brian McGahan (bmcgahan@internetworkexpert.com)
Date: Thu Jan 19 2006 - 13:43:08 GMT-3
Just look at the "show interface switchport" command. It will
tell you if the negotiation of trunking (DTP) is enabled:
Rack1SW1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Rack1SW1(config)#int fa0/1
Rack1SW1(config-if)#do sh run int fa0/1
Building configuration...
Current configuration : 68 bytes
!
interface FastEthernet0/1
switchport mode dynamic desirable
end
Rack1SW1(config-if)#do show int fa0/1 switchport | in Negotiation|Mode:
Administrative Mode: dynamic desirable
Operational Mode: static access
Negotiation of Trunking: On <-----------
Rack1SW1(config-if)#switchport mode access
Rack1SW1(config-if)#do show int fa0/1 switchport | in Negotiation|Mode:
Administrative Mode: static access
Operational Mode: static access
Negotiation of Trunking: Off <-----------
Rack1SW1(config-if)#switchport trunk encapsulation isl
Rack1SW1(config-if)#switchport mode trunk
Rack1SW1(config-if)#do show int fa0/1 switchport | in Negotiation|Mode:
Administrative Mode: trunk
Operational Mode: down
Negotiation of Trunking: On <-----------
Rack1SW1(config-if)#switchport nonegotiate
Rack1SW1(config-if)#do show int fa0/1 switchport | in Negotiation|Mode:
Administrative Mode: trunk
Operational Mode: trunk
Negotiation of Trunking: Off <-----------
Rack1SW1(config-if)#no switchport nonegotiate
Rack1SW1(config-if)#switchport mode dot1q-tunnel
Rack1SW1(config-if)#do show int fa0/1 switchport | in Negotiation|Mode:
Administrative Mode: tunnel
Operational Mode: tunnel
Negotiation of Trunking: Off <-----------
Rack1SW1(config-if)#switchport mode dynamic auto
Rack1SW1(config-if)#do show int fa0/1 switchport | in Negotiation|Mode:
Administrative Mode: dynamic auto
Operational Mode: static access
Negotiation of Trunking: On <-----------
Rack1SW1(config-if)#switchport mode dynamic desirable
Rack1SW1(config-if)#do show int fa0/1 switchport | in Negotiation|Mode:
Administrative Mode: dynamic desirable
Operational Mode: down
Negotiation of Trunking: On <-----------
HTH,
Brian McGahan, CCIE #8593
bmcgahan@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
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> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> James Ventre
> Sent: Thursday, January 19, 2006 8:29 AM
> To: Mitchell, TJ
> Cc: Tim; Ken Young; T.J. Mitchell; Cisco certification
> Subject: Re: DTP
>
> Right. AUTO has to receive a DTP frame to form a trunk. So, if AUTO
and
> ON works, then you know that ON is sending DTP frames. Try the same
> thing with auto/on (w/ switchport nonegotiate).
>
> James
>
> Mitchell, TJ wrote:
>
> AUTO and ON does form a trunk, but it's based on what the other end
has
> configured.
>
> T.J. Mitchell
>
> -----Original Message-----
> From: nobody@groupstudy.com [ mailto:nobody@groupstudy.com ]
On
> Behalf Of
> James Ventre
> Sent: Thursday, January 19, 2006 7:05 AM
> To: Tim
> Cc: 'Ken Young'; 'T.J. Mitchell'; 'Cisco certification'
> Subject: Re: DTP
>
> Another way to also think about this is to consider which DTP/Trunk
> methods work with one another.
>
> Does AUTO and ON form a trunk? If so, why?
>
> James
>
> Tim wrote:
>
> Hey Ken,
>
> You might want to consider these 2 questions --
>
> 1) Does setting the mode to trunk actually disable DTP?
>
> 2) Does disabling DTP on a trunk port disable DTP for the
whole
>
> switch?
>
> Take it from me, success in the ccie lab requires that you first
make
>
> sure
>
> you understand what is required. Only then should you configure
>
> anything.
>
> Tim
>
>
This archive was generated by hypermail 2.1.4 : Wed Feb 01 2006 - 07:45:49 GMT-3